Bridge-gate



(No Model.) 4 Sheet.s-Sheet I. W. E. PRINDLB.

BRIDGE GATE.

No. 562,660. Patented June 23,1896.

(N0 Model.) 4 Sheets-Sheet 2.

l W. E. PRINDLE.

BRIDGE GATE. No. 562,660. Patented June23, 1896.

(No Model.) LE 48heets-Sheet 3. W. E. PRIND BRIDGE GATE.

No. 562,660 Patented June 23, 1896.

(No Model.) 4 SheetsSheet 4 W. E. PRINDLE.

BRIDGE GATE.

No. 662,660. Patented June 23, 1896.

UNITED STATES PATENT OFFICE.

W'ILLIAM E. PRINDLE, OF AURORA, ILLINOIS.

BRIDG E-GATE.

SPECIFICATION forming part of Letters Patent N0. 562,660, dated June 23, 1896.

Application filed October 17, 1895. Serial No. 565,994 (No model.)

To aZZ whom it may concern:

Be it known that 1, WILLIAM E. PRINDLE, of Aurora, in the county of Kane, and in the State of Illinois, have invented certain new and useful Improvements in Bridge-Gates; and I do hereby declare that the following is a full, clear,and exact description thereof, reference being bad to the accompanying drawings, in which- Figure l is a side elevation of a bridge-gate constructed in accordance with my invention, the gate being shown in its open position. Fig. 2 is a like view, the gate being shown as closed. Fig. 3 is an end elevation. Figs. 4 and 5 are detail views of the cam mechanism. Fig. 6 is a detail view in perspective of the devices for lockin g and holding the inner ends of the two parts of the gate when the same is closed. Fig. 7 is a side elevation showing a difierent form of my invention, and Fig. 8 is a diagram showing the manner of determining the length of the hanging levers.

Letters of like name and kind refer to like parts in each of the figures.

The object of my invention is to provide a bridge-gate whose operation shall be perfectly automatic; which shall be easy and noiseless in motion, and with the wear of parts reduced to a minimum; which shall not occupy streetspace, so as to constitute an obstruction, in any degree, to traffic, when it is open; which shall constitute a strong and perfect barrier when closed; and which shall be of such simple construction as to require but little attention to keep it in order, and need but little power to operate it; and to these ends said invention consists in the gate having the construction and combination of parts substantially as and for the purpose hereinafter specified.

My invention is designed for use with a bridge A, of the horizontally swinging or revolving type, but as the construction thereof forms no part of my said invention, I illustrate only a portion of one of its ends.

At each side of the approach to the bridge, on both sides of the stream, I erect a post or standard B, to which, near its lower end, I pivot two upwardly-extendin g levers C and G, that at their upper ends are respectively con nected to two levers D and D, located upon opposite sides of the post, the point of connectlon of each lever C, with its respective lever D, being between the ends of the latter, and at a point above the lower end of the lever D equal to the length of said lever C from its pivot to its said point of connection. The lower ends of the levers D and D are connected to the opposite ends of a gate E, formed of vertical and horizontal bars, while the upper end of each is pivoted to the upper end of a third lever F, which is pivoted at its lower end to the top of the post or standard B.

By the construction of levers shown the gate E will move in an absolutely straight line, and, being rigid and having a set of levers connected with each of its ends, it is perfectly supported and balanced throughout its entire movement back and forth. lYhen the gate is in an extreme position in one direction or the other of its movement, one set of levers is closed or collapsed, while the other is opened out.

For reciprocating the gates E and E, automatically, by the swinging of the bridge, the following-described means are e1nployed,viz: J ournaled in a suitable bracket below the surface of the street, at a point midway between the two posts 13 and B, is a horizontal rock-shaft G, that carries two diametrically-extending arms H and H, that are connected, respectively, by links I and I with downward extensions of the levers O and G, whereby, on the rockiu g of the shaft, the two gates may be simultaneously moved in opposite directions, toward or from each other. Also on said shaft is a two-armed cam K, whose arms are adapted to be alternately engaged, and the cam thus moved, by a roller L, carried by the bridge A. One of said camarms is engaged by the roller as soon as the bridge is started on its opening movement, and operates to cause the gates to be projected toward each other across the passageway, while the other arm is engaged when the bridge has nearly completed its closing movement, and acts to move the gates to free the passage-way. W'hen one arm is thus operated, it swings the other into position for engagement by the roller. The cam-arms are so shaped as to promptly act to move the gates, so as to insure their closing before the bridge has moved very far in its opening movement and to enable the same to be almost closed before the gates are opened, but it will be apparent that any desired time and speed of movement of gates relative to the bridge may be secured by suitably constructing the cam. The gates, when closed, are made to support each other at their inner abutting ends by providing upon one gate two projecting plates L and L, between which the end of the other enters; and as a further support for such ends of the two gates a verticallymovable block M is arranged to engage both on their inner sides, said block being placed and guided within a suitable opening and raised above and lowered below the streetsurface automatically by being connected by a link N with the rock-shaft G. Said block is raised to position simultaneously with the closing of the gates and is lowered simultaneously with the opening thereof, so as to constitute no obstruction. The lower part of each post B is slotted or open, as shown, for the passage of the gate in its reciprocations.

In Fig. 7 I show an embodiment of my invention in which there is a different form of gate than that shown in Figs. 1. and 2, and in which there is but a single set of levers to each gate. In said figure the gate is composed of a number of ropes or chains 0 and O, that at their inner ends pass over pulleys P and P, journaled in a suitable frame Q at the side of the gateway, and have each a weight 0, to carry the chain downward into a well B when the gateway is to be opened. Although I show these two forms of gate, it is to be understood that I do not limit the scope of my invention to either, as my system of levers is applicable to a great variety of construction of gates; nor do I limit myself to the specific mechanism for actuating the gates, nor to means for automatically operating the same.

In Fig. 8 I show a method of readily ascertaining the lengths and points of pivotal connection of my system of levers, which may be described as follows: Draw a horizontal line 1 2, of a length equal to the space to be spanned by the gate, and a line 2 3 perpendicular thereto one-third longer than said line 1 2. Then, with the point 2 as a center and with a radius equal to four-fifths of the line 2 3, strike the are i 5, and with a like radius, and with the point 1 as a center, intersect the are 4 5. These two radii give the length from pivot to pivot of the lever O, and the point of pivotal connection of the same with the lever D. Next divide the line 1 2 into an equal number of partssay five and with each division-point as a center, and with a radius equal to that of the are 4 5, intersect said are, as, indicated at 6, '7, 8, 9, and 10, and from said centers draw lines, respectively, through the latter points. Using said points of intersection successively as centers. and with a radius equal to one-fifth of the line 2 3, lay off on each of the lines above the are 4 5 the points 11, 12, 13, 14, and 15. The latter points are in the arc of a circle whose center is at 16, and whose radius gives the length of the lever E, and the point of its intersection with the line representing the lever D determines the entire length or the latter.

Having thus described my inventiomwhat I claim is- 1. The combination of the two reciprocable gate parts, a lever pivoted to each of said parts, two levers pivotally connected to the other lever, and to a post or other support. and means for simultaneously operating the levers of each gate part, substantially as and for the purpose set forth.

2. The combination of the gate part, the lever pivotally connected thereto, the two levers pivotally connected to the first-named lever, and to a post or support, a two-armed cam, connected with the gate-levers, and a movable bridge having a part adapted to engage the arms of said cam,altern ately, to cause the opening and closing of the gate, substantially as and for the purpose described.

3. The combination of the two reciprocable gate parts, a lever pivoted to each of said parts, two levers pivotally connected; to the other lever, and to a post or other support. a twoearm cam, connected with the levers of 'each gate, and a movable bridge carrying a part to engage said cam-arms, substantially as and for the purpose, specified.

4. The combination of the two reciprocable gate parts having at their inner ends portions to interlock, a lever pivoted to each of said gate parts, two levers pivotally connected to the other lever and to a post or support, a rock-shaft having arms connected to each of said sets of levers, a verticallymovable stop for the gate parts connected with said shaft, a two-armed cam on the shaft, and a movable bridge having a part to alternately engage the cam-arms, substantially as and for the purpose shown.

In testimony that I claim the foregoing l have hereunto setmy hand this 5th day of October, 1895.

IVILLIAM E. PRINDLE.

Witnesses Gno. T. PRINDLE, ADELAID F. PRINDLE.

IOU 

